Josh Grosse <[email protected]> writes:
> On Wed, Nov 17, 2021 at 02:09:50AM +0000, Klemens Nanni wrote: >> On Sat, Nov 13, 2021 at 09:36:21AM -0700, Theo de Raadt wrote: >> > Did the vm previously have a fdc? I doubt it. I am surprised fdcprobe() >> > returns a success. >> >> Turns out fdc(4) attaches only sometimes. Sometimes on cold VM boot, >> sometimes only upon warm reboot. > > I've had consistent results with fdc(4) appearing in VMS on an X220. Bisecting > kernels identified this commit as the root cause: > > 0a894fa656a20dcd3351d61ee4e14415e615ef83 is the first bad commit > commit 0a894fa656a20dcd3351d61ee4e14415e615ef83 > Author: dv <[email protected]> > Date: Tue Aug 31 17:40:59 2021 +0000 > > vmm(4): add ipi for vmclear, unlock kernel > > On Intel VMX hosts, when a guest migrates cpus, VMCS state needs > to be flushed to physical memory before being reloaded on the new > cpu. This diff adds a new ipi to allow a guest resuming on a new > cpu to signal to the old that it needs to vmclear. > > To better surface the potential race conditions, unlock the kernel > after handling the ioctl to vmm and simplify the run loops for both > vmx and svm. This requires a new vcpu lock. > > Tested by some on tech@. "go for it" @mlarkin > > sys/arch/amd64/amd64/cpu.c | 4 +- > sys/arch/amd64/amd64/ipifuncs.c | 13 +- > sys/arch/amd64/amd64/vmm.c | 550 > +++++++++++++++++++------------------- > sys/arch/amd64/include/cpu.h | 6 +- > sys/arch/amd64/include/intrdefs.h | 5 +- > sys/arch/amd64/include/vmmvar.h | 18 +- > 6 files changed, 310 insertions(+), 286 deletions(-) My work adding an ipi for clearing VMCS didn't touch anything to do with emulating instructions touch memory regions. Another thing that changed around this time, IIRC, was we bumped seabios in ports. Can you grab an older "vmm-firmware" from the below, unpack it, and boot the same vm but tell vmctl to use that bios image with -B? http://firmware.openbsd.org/firmware/6.9/vmm-firmware-1.11.0p3.tgz I would be shocked if my ipi work magically made vmm or vmd start showing a floppy disk device. -dv
